Route 85 was commissioned in 1932 from the old SH 102 (New London to Colchester) and SH 366 (Hebron to Bolton). The portion south of Colchester follows the 19th-century New London Turnpike road.

Route 85's north end has flipped a few times. It originally entered Manchester along Camp Meeting Road (SR 534) to end at Route 83 (or somewhere short of there). According to state highway maps, it was shifted north to meet US 6 and 44 in Bolton (near today's terminus, if not at it). In 1954, it was shifted back to Camp Meeting Road.

On Mar. 29, 1963, it was moved for the last time to its current route. It took over former SR 807 (Clark Road and Bolton Center Road) to US 6/44, and Camp Meeting Road became SR 534.

Even after that, the northbound Route 85 mainline followed SR 534 toward Manchester; to continue on 85 was a right turn. Around 2000 this intersection was rebuilt into a conventional T-intersection.

A 1931 study by the Traffic Section Department of Motor Vehicles called for a traffic circle at the Salem intersection with Route 82, but this never came about.

Proposed Freeway becomes Route 11

Statewide plans in the 1950s included a freeway connecting Hartford and New London, using Routes 2 and 85. The Route 85 freeway would extend from Route 2 in Colchester to US 1 in Waterford.

Part of this road was built in 1972, from Route 2 in Colchester to Route 82 in Salem. In July 1971, however, the DOT had announced that in order to minimize motorist confusion and signing costs, the old Route 85 would keep its number. The new Route freeway opened as Route 11, and there's much more history on the Route 11 page.

In 1956, Route 85 was reconstructed in the Gilead area of Hebron. Salt Box Road and Prentice Hill Road are old alignments of the route.

In 1984, Route 85 was widened to four lanes with a median near the newly opened Crystal Mall in Waterford.

Finishing Route 11

Increased traffic in the southeast has prompted plans that include widening Route 85 to six lanes between Salem (the end of Route 11) and New London; however, the state and local residents are pushing for the completion of Route 11 instead.

Route 85 is heavily commercialized in the area between I-95 and I-395 in Waterford, with growing congestion and high speeds.

Spot improvements to Route 85

As a new expressway will not be ready until about 2010 20-something, the state has pursued small safety and capacity improvements along Route 85, including:

• climbing lane between Forsyth Road and Horse Pond, Salem, and near Turner Road, Montville
• additional thru lanes at Grassy Hill Road and Route 161
• wider shoulders
• widening and a raised divider at Route 82

Route 85 is the only state route to intersect both I-384 and I-395.

Extend northward along SR 533 and SR 527 to the Route 83/74 split in north Rockville. At least one map typo has inadvertently supported this idea.

"It's a road built in the 1800s and has 13 stoplights."

Jane Dauphinais, district director for U.S. Rep. Rob Simmons, R-2nd District, explaining why Route 85 would not serve as well as a completed Route 11 for emergency evacuation purposes

• "Routes Changed on State Roads." Hartford Courant, Mar. 1, 1963.
• "Heart Fund Nets $425 in Drive." Hartford Courant, Mar. 26, 1963. (SR 807 to CT 85)
• "Agency reports new Rt. 85 to get Rt. 11 designation." Hartford Courant, July 22, 1971.
• "Transportation board to tackle state's traffic woes." Hartford Courant, Nov. 2, 2001.
• "Extensive work designed to improve safety of Route 85." The Day [New London, Conn.], May 17, 2002.
• "Making Route 85 safer." Editorial, The Day [New London, Conn.], May 20, 2002.
• Adams, Thomas. "The Buell Farm in Gilead CT." http://www.rockvillemama.com/buellfarm.htm (30 August 2003)
• "Speed Alley in Waterford." The Day [New London, Conn.], Dec. 1, 2003.